[PATCH 2/2] mtd: nand: raw: atmel: Add error handling when rb-gpios missing

[Eugen Hristev]

Hi,

On 8/8/23 18:03, Alexander Dahl wrote:
> Hello Michael,
> 
> Am Tue, Aug 08, 2023 at 03:49:45PM +0200 schrieb Michael Nazzareno Trimarchi:
>> Hi
>>
>> On Tue, Aug 8, 2023 at 3:03 PM Alexander Dahl <ada at thorsis.com> wrote:
>>>
>>> Adapt behaviour to Linux kernel driver.
>>>
>>> The return value of gpio_request_by_name_nodev() was not checked before,
>>> and thus in case 'rb-gpios' was missing in DT, rb.type was set to
>>> ATMEL_NAND_GPIO_RB nevertheless, leading to output like this for
>>> example (on sam9x60-curiosity with the line removed from dts):
>>>
>>>      NAND:  Could not find valid ONFI parameter page; aborting
>>>      device found, Manufacturer ID: 0xc2, Chip ID: 0xdc
>>>      Macronix NAND 512MiB 3,3V 8-bit
>>>      512 MiB, SLC, erase size: 256 KiB, page size: 4096, OOB size: 64
>>>      atmel-nand-controller nand-controller: NAND scan failed: -22
>>>      Failed to probe nand driver (err = -22)
>>>      Failed to initialize NAND controller. (error -22)
>>>      0 MiB
>>>
>>> Note: not having that gpio assigned in dts is fine, the driver does not
>>> override nand_chip->dev_ready() then and a generic solution is used.
>>>
>>> Fixes: 6a8dfd57220d ("nand: atmel: Add DM based NAND driver")
>>> Signed-off-by: Alexander Dahl <ada at thorsis.com>
>>> ---
>>>   drivers/mtd/nand/raw/atmel/nand-controller.c | 11 +++++++----
>>>   1 file changed, 7 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c
>>> index 2b29c8def6..8e745a5111 100644
>>> --- a/drivers/mtd/nand/raw/atmel/nand-controller.c
>>> +++ b/drivers/mtd/nand/raw/atmel/nand-controller.c
>>> @@ -1600,10 +1600,13 @@ static struct atmel_nand *atmel_nand_create(struct atmel_nand_controller *nc,
>>>                          nand->cs[i].rb.type = ATMEL_NAND_NATIVE_RB;
>>>                          nand->cs[i].rb.id = val;
>>>                  } else {
>>> -                       gpio_request_by_name_nodev(np, "rb-gpios", 0,
>>> -                                                  &nand->cs[i].rb.gpio,
>>> -                                                  GPIOD_IS_IN);
>>> -                       nand->cs[i].rb.type = ATMEL_NAND_GPIO_RB;
>>> +                       ret = gpio_request_by_name_nodev(np, "rb-gpios", 0,
>>> +                                                        &nand->cs[i].rb.gpio,
>>> +                                                        GPIOD_IS_IN);
>>> +                       if (ret)
>>> +                               dev_err(nc->dev, "Failed to get R/B gpio (err = %d)\n", ret);
>>
>> Should not then an error here
> 
> Different log level or no message at all?
> 
> Note: Linux prints the same message with error level in that case.
> 
> Greets
> Alex
> 

Since the rb-gpios is optional, we can continue probing without it. 
Throwing an error message is optional and pure informative. So I am fine 
with it

What I wanted to ask is what happens with nand->cs[i].rb.type , is it 0 
by default ?

Other than that, I can apply this patch, Michael, do you have any more 
comments on it ?

Thanks,
Eugen
>>
>> Michael
>>
>>> +                       else
>>> +                               nand->cs[i].rb.type = ATMEL_NAND_GPIO_RB;
>>>                  }
>>>
>>>                  gpio_request_by_name_nodev(np, "cs-gpios", 0,
>>> --
>>> 2.30.2
>>>
>>
>>
>> -- 
>> Michael Nazzareno Trimarchi
>> Co-Founder & Chief Executive Officer
>> M. +39 347 913 2170
>> michael at amarulasolutions.com
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>>
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